Device for dressing profiled grinding wheels



Jan. 2.2, 1935. GoDzlEwsKl 1,988,895

DEVICE OR DRESSING PROILED GRINDING WHEELS Filed Sept. 1, 1955 3Sheets-Sheet 2A Y l l A y l A A enna/1h Gola/bush' u. 7 Maw.:

l Jam 22, 189.35; H. GoDzu-:wsKl l .1,988,895

DEVICE FOR DRESSING-PROFILED GRINDING WHEELS Filed Sept. l, 1953 3Sheets-Shea?l 3 Patented .lan. 22, 1935 UNITED STATE DEVICE ronVDRESSING PnomED GRINDTNG WHEELS Hermann Godziewski, Eichwalde,

assignor to Herbert m. b. H., Berlin-Witteman, Germany,

Germany,

corporation Application I Kreis Teltow, Lindner G. a limited September1, 1933, Serial No. 687,883 n Germany May 23, 1933 11 claims.(c1.125'11) The two positions of the lever are limited by 6 the profileof the grinding wheel.

Means have previously been employed to dress profiled grinding wheels bya copying process in which a diamond controlled by means f a linkparallelogram is employed. A dressing device has also already beenemployed comprising two slides mounted on a rotary axle, which areconnected through a lever system with one another. ,The oneslide carriesthe dressing tool and the other a tracer which is guided over a former.The first mentioned devices can only be constructed in grinding machinesin a complicated manner and require a comparatively large space. In thelast mentioned device only a shaped diamond can be used, which operateswith at least two corners and the intermediate edge of its prole. Apartfrom the fact that a shaped diamond is costly and less durable in usethan a rough diamond, there are also difficulties in keeping the traceralways exactly in accord with the cutting edges of the dressing toolsubjected to the wear.

The device according to the invention does not show these disadvantages.Its principal features are as follows:

Two dressing tools are secured side by side a predetermined distanceapart on a two-armed lever, which dressing tools can be normal shapeddiamondsy or grinding tools of very hard material. This double lever ismovable about a rotary axis, which lies in a plane parallel to the axisof the grinding wheel, as well as about an axis perpendicular t-o theplane of the grinding wheel prole, and these movements are effected fromlthe tracer guided over a former or pattern,l

the tracing arm turning its guide member t0- gether with the doublelever connected therewith and the dressing tools and at the same timeoperating over suitable intermediate members, for instance a toothedrack and toothed wheel, a cam, which so operates on the double lever,that the dressing tools move in a radial direction to and from thegrinding wheel. The double lever carrying the dressing tools isarranged, with the cam which controls its movement to and from thegrinding Wheel, in a rotary shaft of the guide member of the tracingarm. In order, after the completion of one profile-half to bring the onedressing tool out of engagement with the grinding wheel and the otherinto operative position, the double lever is movable in the direction ofits rotary axis. v v

means of stops, able. A spring-pressed lever against the operative stop.

shaft, on which the double s PATENT oFFicE of which at least one isadjustpin presses the double The rotary lever is mounted, projects fromits bearing and is provided with two oblique surfaces, which tion of thetracer at the base move the shaft-with the axially in one or other Inthis way when the dressing of the stationary stops and lever anddressing tools direction.

abut in each end-posiof the former against one profile-half hasbeencompleted, one dressing tool is automatically brought into and the otherout of the operative position. The carrier for the dressing tools on thelever and in such a ting edge of a dressing position over the centre ismovably arranged manner that the cuttool can be adjusted to a line ofthe prole to be produced. The whole device is arranged in a slide, whichis adjustable in suitable guides with respect to the grinding wheel,

for location of the dressing tools and in order to allow for thedecreasing diameter of the grinding wheel.

An embodiment of the invention is illustrated in the accompanyingdrawings, in which Figure 1 is a view in longitudinal section of thesaid embodiment,

Figure 2 is a plan view,

Figure 3 is a transverse I-I of Figure 1,

section on the line Figure 4 is a transverse section on the line II-IIof Figure 3,

Figures 5 to 7 show the dressing tools in various operative positions,the arrangement here shown being that for the production of Whi fordressing a grinding wheel tworth threads.

Figure 8 shows the cam path of the guide cam for the tool lever.

Figure 9 is a plan view,

partly in section, of

the completedevice, its mounting and hood.

Figure 10 is an elevation,l

partly in section,

from the right side of Figure 9, the view being turned to erectposition.

Referring now to the tools 1 and 2 are secured holder 3 mounted on onedrawings, the dressing side by side in a tool end of a two-armed 5 ismounted in the bearings 6 and 7 in a rotary hollow stub shaft 8'extending from the member 8. The axis y-y ofthe r otary shaft 8' isperpendicular to rthe plane of the profile of the grinding wheel S. Itneed not, as shown in the drawings, pass through the but can passoutside this.

axis of rotation :1r-x, The member 8 serves as a guide member for thetracing arm v9, which carries the tracing roller 11 guided over theformer or pattern 10. The former 10 is secured on a slide 12, which isprovided with a bearing for the rotary shaft 8. 'I'he tracing arm 9 hasa toothed rack 9', which engages with a toothed wheel 13. With thetoothed wheel 13 is connected a cam 14, which rotates with the toothedwheel on a shaft 15 arranged in the rotary shaft 8'. The lever 4 carriesa lug 4' which is pressed continuously by a spring 16 against the cam14. For effecting the rotation of the cam a steel band, rope or the likeunder tension, can also be secured to the tracing arm 9, so as to windon or off a drum connected with the cam and so rotate the latter.

The distance measured from the point of contact of the tracer 11 withthe former 10 to the axis y-y of the rotary shaft 8' bears apredetermined relation to the distance measured from the point ofcontact of the dressing tool 1 or 2 with the grinding wheel S to theaxis y-y of the rotary shaft 8'. The throw of the cam 14, taking intoaccount the proportion of the lever arms of the lever 4 to one another,is properly proportioned with respect to the length of the prole of theformer 10.

If now the tracer 11 is guided along the former, then the tracing arm 9,through'the rack 9', the toothed wheel 13 and the cam 14, causes amovement of the lever 4, due to which that dressing tool situated in theoperative position moves in a radial direction to or from the grindingwheel.

. At the same time, however, through the tracing arm 9, the guide member8 and shaft 8', together with the lever 4 and the dressing tools isrotated around the axis y-y, so that the dressing i tool executes,corresponding to the proii'le angle of the former 10, a movement in thedirection of the axis of the grinding wheel. In this way there isproduced on the grinding wheel a prole,

which corresponds exactly with the former in a proportion correspondingto the transmission ratio of the elements transmitting the movements.The shape of the cam 14 is shown in Figure 8. The cam path begins at thepoint a and continues to the point b. The greatest elevation of the campath corresponds, in the proportion of the transmission ratio to theheight of the profile of the largest former for the largest grindingwheel proiile to be produced by I neans of the dressing device. The camcan, therefore, also be used for all smaller grinding wheel profiles..The rack 9' then moves the cam, corresponding to the lowerprofile-height of the former, only through a fraction of the path a-b.

As already mentioned, only one dressing tool is in operative position atany time during the dressing process and shapes one half of the profile,while the other dressing tool is out of engagement with the grindingwheel. For this the two dressing tools 1 and 2 are arranged a distance Aapart in the support 3. The space A is somewhat larger than the actualprofile-base or' breadth of the grinding wheel. The dressing tools areso adjusted in the support 3 that their operative cutting-edges are thesame distance from the axis matically eiiected since, as soon as thetracer 11 is guided over the respective end-position at the base of theprofile of the former, an extension 5', projecting out of the bearing 6of the shaft 5, engages with one or other of stop-surfaces 1'1 and 18formed on said extension 5', in consequence of the rotary movement ofthe shaft 8' against one or other of stops 19 and 20 and thereby causesthe shaftl 5 to be shifted axially with the lever 4 and the dressingtools. 'Ihe stops 19 and 20 are secured to the part 12' of the slide 12.When the surface 1"I strikes against the stop 19 the lever 4 is movedwith the shaft 5 into contact with the adjustable stop 21. the shaft 8in the other direction, the stop-surface 18 strikes against the stop 20,and the shaft 5 with the lever 4 is moved to engage the stationary stopsurface 22. 'I'he dressing tools 1 and lever 4 and in such a manner thatthe cuttingl.

edges of each dressing tool can be adjusted exactly to a position overthe centre line of the prole to be produced. For the adjustment of thecarrier 3 two screw bolts 30 and 31 are used which are secured to thelever 4 in a suitable manner.

The slide 12, which serves for the reception of the whole dressingdevice and the former, is movable in vsuitable guides in theparticularly rigidly constructed protecting cover 27 for the grindingwheel S. It can, by means of the screw-spindle 28 which co-operates witha nut 29, be adjusted with respect to the grinding wheel. The screwspindle 28 can thereby be so connected with the screw spindle for theadjustment of the grinding wheel support that the grinding wheel isautomatically re-adjusted with respect to the work by the amount of thedressing, lso that after the dressing of the grinding wheel the lattercan be operated again without measurement being required.

Arranged in the upper part of the grinding wheel support 27' is theadjusting spindle 36 for adjusting' the grinding wheel support and thedressing device. Mounted upon the adjusting spindle 36 is a worm 37engaging a worm wheel 38. The worm wheel shaft 39 is journaled in thegrinding wheel support 27' and carries at its lower end a toothed pinion40 `engaging a rack 4l fixed to the stationary base 41 of the machine.Mounted upon the rear end of the adjusting spindle 36 is a gear 42driving a gear 44 by means of an idler gear 43. The'gear 44 is mountedupon the adjusting screw spindle 28 for the dressing device. Gear 44drives the ad justing spindle 28 by means of a friction clutch 45. 'I'heclutch member 45' is longitudinally displaceable along the spindle 28 bymeans of a wedge 46. The adjusting nut 47, upon being tightened, pressesthehand wheel 48 upon the clutch member 45', thereby clutching the gear44 to the adjusting spindle 28. The transmission of motion from theadjusting spindle 38' Upon rotation of vmeans of the worm gearprotecting cover or hood, is the dressing device."

When dressing of the grinding wheel S becomes necessary, the grindingwheel S is moved out lof engagement with the work piece W whereupon thehandwheel 49 is turned to an extent indicated upon the scale 49 by thepointer 50. In this way. an adjustment of the grinding wheel support 27toward the work piece is effected by gearing and rack and pinion 40, 41.

At the same time the dressing device is advanced `in its guideways (bymeans of the gears 42, 43, 44) toward the grinding wheel S for the sameextent.- In other words, the grinding wheel is automatically adjustedwith respect to the work piece for wearpcaused through the grinding andfor the extent desired for dressing. Therefore, after the dressing hastaken place no further correction is necessary in the radial adjustmentof the effective grinding wheel profile with respect to the work piece Wand grinding can be continued without prior testing.

If a grinding wheel of a different diameter is to be mounted on thegrinding spindle, the adjusting means for the dressing device have to bedisengaged from the Amain adjusting spindle 36. For this purpose, thegear -44 is moved-out of engagement with the spindle 28 throughloosening of the adjusting nut 47 and of the friction clutch 45, 45',whereupon the dressing device is adjusted with respect to the grindingwheel S by means of the hand wheel.

The dressing device according to the invention can also be furnishedwith a single dressing tool which shapes the grinding wheel prole to beproduced by two corners and the intermediate edge of its profil For thisthe stops 19 and 20 are removed and the adjustable stop screw 21 soscrewed against the shaft that the lever 4 lis immovable in thedirection of its rotary axis.

The use of two dressing tools is, however, preferred as in this case thedisadvantages mentioned hereinbefore-shaping of the tracerare avoided,andonly a simple cylindrical tracing roller is required.`

The dressing device illustrated in Figures 1 to 8 may, if desired, beadapted for use with a single dressing tool. For this the stops 19 and20 are removed and the adjustable stop screw 21 so screwed againsttheshaft 5 that the lever 4 is immovable in the direction of its rotaryaxis.

All shapes of grinding wheels can be dressed with the device constructedin accordance with the invention.

1. A device for dressing profiled grinding wheels, comprising twodressing tools controlled by means of a lformer and of which each,operates on a respective half of the grinding wheel profile, in whichthe dressing tools are mounted side by side on a two-armed lever adaptedto turn about an axis of rotation which is in a plane parallel to theaxis of the grinding wheel and also about an axis perpendicular to theplane Vof the grinding wheel profile, the turning move-f ments of thelever being effected by a tracer guided over a former, the tracing armcausing its guide member and a rotary shaft connected therewith torotate together with the lever and dressing tools and at the same timeoperates, through the intermediary of suitable members, for example atoothed rack and toothed wheel, a cam which acts on the lever in such amanner asto cause the dressing tools to move radially with respect tothe grinding wheel.

37, 38, and the toothed l 2. A device as claimed in claim 1, in whichthe double lever carrying the dressing tools is arranged, with the camcontrolling its movement to and from the grinding wheel, in the rotaryshaft of the guide member for the tracing arm.

3. A device as claimed in claim 1, in which the double lever is movablein the direction of its rotary axis in order that when onehalf of theprofile has been dressed the one dressing tool may be brought out ofengagement with the grinding wheel and the other brought into operativeposition.

4. A device for dressing profiled grinding wheels, comprising a support,a former pattern mounted thereon, a grinding wheel spindle mounted torevolve on a fixed axis, a shaft mounted in said support to rotate on anaxis perpendicular to the periphery of a grinding wheel on said spindle,a lever pivoted intermediate its ends to said shaft to swing about anaxis perpendicular to the shaft, grinding wheel dressing means carriedby one end of said lever to engage the periphery of a grinding wheelmounted on said spindle, and guide means for rotating said shaft on itsaxis and swinging said lever and including means to engage the formerpattern.

5. A device for dressing profiled grinding wheels comprising a support,a former pattern mounted thereon, a grinding wheel spindle mounted torevolve on a xed axis, a shaft mounted in said support to rotate on anaxis perpendicular to the periphery of a grinding wheel on said spindle,a lever pivoted intermediate its ends to said shaft to swing about anaxis perpendicular to the shaft, grinding wheel dressing means carriedby one end of said lever to engage the periphery of a grinding Wheelmounted on said spindle, a head on said shaft, a guide bar slidablymounted in said head to reciprocate transversely of the shaft and havingmeans on its outer end to engage the former pattern, and meansconnecting the bar and lever to oscillate the lever as the bar isprotracted and retracted.

6. A device for dressing profiled grinding wheels comprising a support,a former pattern mounted thereon, a grinding wheel spindle mounted torevolve on a fixed axis, a shaft mounted in said support to rotate on anaxis perpendicular to the periphery of a grinding Wheel on said spindle,a lever pivoted intermediate its ends to said shaft to swing about anaxis perpendicular to the shaft, grinding wheel dressing means carriedby one en'd of said lever to engage the periphery of a grinding wheelmounted on said spindle, a head on said shaft, a guide bar slidablymounted in said head to reciprocate transversely of the shaft and havingmeans on its outer end to engage the former pattern, means connectingthe bar and lever to oscillate the lever as the bar is protracted andretracted, stops limiting the movement of oscillation of said lever andmeans to adjust the position of at least one of said stops.

7. A device for dressing profiled grinding wheels comprising a support,a former pattern mounted thereon, a grinding wheel spindle mounted torevolve on a fixed axis, a shaft mounted in said support to rotate on anaxis perpendicular to the periphery of a grinding Wheel on said spindle,a lever pivoted intermediate its ends to said shaft to swing about anaxis perpendicular to the shaft, grinding wheel dressing means carriedby one end of said lever to engage the periphery of a grinding Wheelmounted on said spindle, a head on said shaft, a guide bar slidablymounted in said head to reciprocate transversely of the shaft and havingmeans on its outer end to engage the former pattern, means connectingthe bar and lever to oscillate the lever as the bar is protracted andretracted, stops limiting the movement of oscillation of said lever,means to adjust the position of at least one of said stops, and a springholding said lever against the adjustable stop.

8. A device for dressing proled grinding wheels comprising a support, aformer pattern mounted thereon, a grinding Wheel spindle mounted torevolve on a fixed axis, a shaft mounted in said support to rotate on anaxis'perpendicular to the periphery of a grinding wheel on said spindle,a lever pivoted intermediate its ends to said shaft to swing about anaxis perpendicular to the shaft, grinding wheel dressing means carriedby one end of said lever to engage the periphery of a grinding wheelmounted on said' spindle, guide means for rotating said shaft on itsaxis and swinging said lever and including means to engage the formerpattern, a base whereon said support is slidably mounted to move towardand from the axis of said spindle, and means to move the support and theparts carried thereby toward and from said spindle.

9. A device for dressing profiled grinding wheels comprising a support,a former pattern mounted thereon, a grinding wheel spindle mounted torevolve on a fixed axis, a shaft mounted in said support to rotate on anaxis perpendicular to the periphery of a grinding wheel on said spindle,a lever pivoted intermediate its ends to said shaft to swing about anaxis perpendicular to the shaft, grinding wheel dressing means carriedby one end of said lever to engage the periphery of a grinding wheelmounted on said spindle, a head on said shaft, a guide bar slidablymounted in said head to reciprocate transversely of the shaft and havingmeans on its outer end to engage the former pattern, means connectingthe bar and lever to oscillate the lever as the bar is protracted andretracted, a base whereon said support is slidably mounted to movetoward and from the axis of the said spindle, and means to move thesupport and the parts carried thereby toward and from said spindle.

10. A device for dressing profiled grinding wheels comprising a support,a former pattern mounted thereon, a grinding wheel'spindle mounted torevolve on a fixed axis, a shaft lmounted in said support to rotate onan axis perpendicular tothe periphery of a grinding wheel on saidspindle, a lever pivoted intermediate its ends to said shaft to swingabout an axis perpendicular tothe shaft, grinding wheel dressing meanscarried by one end of said lever to engage the periphery of a grindingwheel mounted on said spindle, a head on said shaft, a guide barslidably mounted in said head to reciprocate transversely of the shaftand having means on its outer end to engage the former pattern, meansconnecting the 'bar and lever to oscillate the lever as the bar isprotracted and retracted, stops limiting the movement of oscillation ofsaid lever, means to adjust the position of at least one of said stops,a base whereon said support is slidably mounted to move toward and fromthe axis of said spindle,

and means to move the support and the parts carried thereby toward andfrom said spindle.

11. A device for dressing profiled grinding wheels comprising a support,a former pattern mounted thereon, a grinding wheel spindle mounted torevolve on axed axis, ashaft mounted in said support to rotate on anaxis perpen-' dicular to the periphery of a. grinding wheel on saidspindle, a lever pivoted intermediate its ends to said shaft to swingabout an axis perpendicular to the shaft, grinding wheel dressing meanscar- 'ried by one end of said lever to engage the pe' riphery of agrinding wheel mounted on said spindle, a head on said shaft, a guidebar slidably mounted in said head to reciprocate transversely of theshaft and having means on its outer end to engage the former pattern,means connecting the bar and lever to oscillate the lever as the bar isprotracted and retracted, stops `limiting the movement of oscillation ofsaid lever, means to adjust the position of at least one of said stops,a spring holding said lever against the adjustable stop, a base whereonsaid support is slidably mounted to move toward and from the axis ofsaid spindle, and means to move the support and the parts carriedthereby toward and from said spindle.

HERMANN GODZIEWSKI.

